Bent sheet detector



Oct. 28, 1952 J. SIMPSON 2,616,001

BENT SHEET DETECTOR Filed Aug. 2, 1949 INVENTOR J/sfin I Simpson '7 ZLu M,

ATTORNEYS Patented Oct. 28, 1952 BENT SHEET DETECTOR Justin Simpson, Elmhurst, Ill., assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New York Application August 2, 1949, Serial No. 108,191

3 Claims.

The invention relates generally to the handling and conveying of can body blanks or like metallic sheets and primarily seeks to provide a novel means for detecting the passage of a blank or sheet having an improperly bent or displaced edge portion and automatically discontinuing the feeding of said blank or sheet.

While the invention is subject to other adaptations, it is primarily adapted for use in apparatus in which can body blanks ultimately intended to be made into can bodies are fed along in processional order with the marginal edge portions which are to be formed into can body side seams extending laterally beyond the conveying means and travelling in a longitudinal direction. One apparatus of this character is disclosed in the copending application for U. S. Letters Patent, Serial Number 108,173, filed by Scott R. Johnson on August 2, 1949. This application apparatus has to do with the deoxidizing of the marginal edge portions of the blanks which are to form the can body side seams, and said edges are acid cleaned, Water washed and hot air dried while being conveyed in the manner stated. The deoxidized blanks may be stored temporarily after being cleaned, or they may be directly fed into a bodymaker to be formed into can bodies, but it will be obvious that in either case, to feed a blank into the bodymaker with an edge portion thereof bent of line would result in a jamming of machine parts, or the formation of a leaky side seam. It sometimes happens that the conveyed blanks are of the type from which tear strip cans are formed, and in such cases equal care must be exercised in assuring against the feeding in of a can body blank having a tear strip tongue extension bent out of line. It is the purpose of the present invention to provide novel means for detecting the presence of a bent edge or corner or tongue extension on a blank being fed, and for utilizing the movement of said faulty edge, corner or tongue extension in bringing about an automatic stopping of the blank feed.

In its more detailed nature, the invention resides in providing, in combination with the means for feeding the blanks and the source of :electromotive force which drives said means, switch means connected in the power source line, and means including a displaceable member having a narrow slot therein through which edge portions of normal sheets or blanks can freely pass, but which will not freely pass an improperly bent edge, corner or tongue extension of a blank or sheet, and which will be displaced by contact of such a moving bent edge, corner or tongue 2 extension, there being included means effective upon such displacement of the slotted member to actuate the switch to cut off the electromotive force and discontinue the feeding of the faulty blank.

Another object of the invention is to provide faulty sheet detecting and drive stopping means of the character stated in which a control device including the slotted and displaceable member is placed at each side of the blank or sheet feedway so as to provide for a testing of each laterally extended marginal edge portion of each blank or sheet fed over the feedway, said devices being connected in series in the power source line so that displacement of either displaceable member by a bent corner, edge or tongue extension of a blank will actuate the respective switch to cut off the electromotive force and discontinue the feeding of the faulty blank.

Another object of the invention is to provide control means of the character stated in which each control device includes a support, a switch mounted on the support and having an. actuator element thereon, a tester member swingably mounted on said support and having an angularly disposed extension equipped with a narrow slot therein through which edge portions of normal sheets or blanks can freely pass but which is too narrow to pass an improperly bent sheet or blank edge, corner or tongue extension, means for yieldably retaining said extension in position for having travelling sheet or blank edge portions pass therethrough and for permitting the tester member to swing out of its normal position whenever it is contacted by an improperl bent edge, corner or tongue extension of a travelling sheet or blank, and means movable with the tester member when it is so displaced and cooperating with the actuator element of the switch in a manner for bringing about a circuit open condition of the switch each time the tester member is so displaced.

Another object of the invention is to provide a control means of the characte stated in which the switch is of the normally open type, and the extension from the tester member normally is yieldably held against the switch actuator meinber by a spring detent in position to hold the switch actuator member in a switch closing position.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the ap- 3 pended claims and the several views illustrated in the accompanying drawing.

In the drawing:

Figure 1 is a vertical cross section illustrating the improved faulty sheet detecting and drive stopping means applied to a can body blank feedway.

Figure 2 is a side elevation of the apparatus shown in Figure 1.

Figure 3 is a fragmentary plan view illustratin the control device at one side of the can body blank feedway.

Figure 4 is a detail vertical cross section taken on the line 4-- on Figure 1.

In the example of embodiment of'the invention herein disclosed, the faulty sheet or blank detecting and drive stopping meansis adapted. for use in connection with apparatus of the type disclosed in the copending application for U. S. Letters Patent filed by Scott R. Johnson on August 2, 1949, said application being identified by Serial No. 108,173. In the application referred to can body blanks arefed in .processional order by motor driven means through several treating stations designed for the purpose of removing oxidation and scale so as to facilitate subsequent solder bonding of portions of said blanks. In said application the blanks are held in downwardly bowed relation while being fed, but it is to be I understood that thepresent invention is not limited to the testing of blanks fed in this bowed condition, or to any particular form of conveyor means or'drive therefor, except that the same be electrically driven so that the control devices can operate to permit or prevent the flow of electrical energy to the driving means. The application referred to discloses an example conveyor drive in detail. This drive is diagrammatically illustrated herein in the form of a motor.

In this sample disclosure can body blanks 5 such as are intended ultimately to be formed into tear strip cans and which include the usual tear strip tongue extensions 6 are shown as being conveyed and held in downwardly bowed relation by the lugs on a pair of conveyor chains 8, the upper and lower flights of which travel in upper and lower guides 9, I2 supported at I! on suitable framing |2. While being fed, the blanks are supported centrally on a longitudinal support member |3, and the laterally extended, ,longi- I tudinally travelling marginal edge portions Hi of the blanks extend well beyond the upright walls l5 which are provided at their lower edges with rounded portions |6 serving as guide means assisting in the holding down of the laterally extended portions of the blanks in the manner clearly illustrated in Figure 1.

At each side of the feedway a support member I! is secured as at Hi to the chain supporting means, and a switch IQ of the normally open type is secured to each support member. Each switch includes the usual actuator element or plunger 20, and it is to be understood that when this plunger is thrust inwardly it will serve to hold the switch contacts together or in the circuit completing condition. Whereas, when said plunger is released, it will move to its normal projected position and permit the contacts to separate and break the circuit through the switch. It will be apparent from the diagrammatic illustration in will serve as the power source through which the conveyor chains 8 are driven. However, should either or both of the switches I9 be allowed to assume their normally open condition, the power circuit through the motor M will be broken and the driving of the chains 8 will be discontinued. A tester member generally designated 24 cooperates with each of the switches l9, and each said member includes an upright or standard 25 which is pivotally supported at 26 on the respective support member Each standard 25 is provided at its upper end with an angle bent portion 21 which is slotted as at 28 to straddle the laterally extended marginal edge extremities of the blanks in the manner clearly illustrated in Figure 1. The detector slots 28 are very narrow. While they will freely pass normally, undamaged edge portions of the blanks 5, any bent edge, corner or tongue extension 6 would engage in the slot, and being unable to pass freely through the slot would cause the standard 25 to turn on its pivotalmounting, or inother words be displaced .by the travelling, faulty or bent portion of the blank. The detector member slots preferably are flanked by guide wings 29 which extend in both directions from the slot in the manner clearly illustrated in Figures 2 and 3.

Each detector standard 25 also is equipped with an actuator arm extension 30, and it will be apparent by reference to Figures 1 and 3 of the drawings that each said extension lies in the same vertical plane with the corresponding angle bent upper end portion 21. This symmetrical arrangement of the tester member parts, including the double projection of the wings 29, makes it possible to use each tester member for either right or left mounting.

The standard extension 30 of each tester member normally overlies a detent head 3| which is recessed as at 32 to receive the same in the manner clearly illustrated in Figure 4. Each head 3| is mounted on the upper end of a plunger 33 which passes downwardly through and is slidable in a bore 34 formed in the respective support H. The plunger heads 3| are movable in counterbores 35, and a spring mounted in each counterbore beneath the respective head 3| serves to yieldably urge the respective plunger in an upward direction to the extent permitted by the adjustable limiting stop 31.

The spring projected plunger 33 in each of the detector units serves to hold the extension 30 against the associated switch actuator plunger 2|] in a manner for retaining the circuit closing condition of the switch. However, should a can body blank 5 be fed along by the lugs l in the direction of the arrow A in Figure 2 and have a bent edge portion, a bent corner or a bent tongue 6 which wouldnot pass freely through the narrow slot 28 in a detector extension 27, it would swing the detector extension out of the way, displacing the arm extension-30 and permitting the respective spring actuator plunger 20 to spring out to bring about the normal circuit opening condition of the switch, thereby breaking the circuit through the driving motor M and causing a discontinuance of the feeding of the faulty blank 5. It will be understood that should bent edges, corners or tongue portions be included at either or both sides of the feedway, so as to bring about a displacement of one or both of the detector members, the circuit through the driving motor M would be'broken'and the movement of the feeder chains 8 would be stopped.

While one form of the invention has been shown for purposes of illustration, it is to be clearly understood that various changes in the details of construction and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In apparatus of the character described, a control unit including a support, a detector member having an upright standard mounted on said support to swing about a vertical axis, a tester extension extending in generally horizontal direction from said standard and equipped with a tester slot so narrow as to freely pass only normal sheet edge portions free of abnormal bends, a switch actuator extending in generally horizontal position from the standard and movable therewith, a normally open switch including a normally projected plunger disposed to be placed inwardly in switch closing position by contact with said switch actuator when the tester extension is extended in its normal testing position and to move outwardly to the switch opening position whenever the switch actuator moves away from said plunger incidental to a displacement of the tester extension by a bent edge portion of a blank, and a spring plunger spring detent positioned to yieldably press against the switch actuator when said actuator is in its normal testing position and yieldably hold said actuator against the switch plunger in said normal testing position.

2. A control unit as defined in claim 1 in which the tester extension and the switch actuator extend from the detector member standard in the same direction and in a common vertical plane, 3

and the slot in the tester extension is flanked by flared lead-in guides extending symmetrically in opposite directions therefrom so that the detector may be used universally as a right or left element.

3. In apparatus of the character described, a control unit including a support, a detector member having an upright standard mounted on said support to swing about a vertical axis, a tester extension extending in generally horizontal direction from said standard and equipped with a tester slot so narrow as to freely pass only normal sheet edge portions free of abnormal bends, a switch actuator extending in generally horizontal position from the standard and movable therewith, a normally open switch including a normally projected plunger disposed to be displaced inwardly in switch closing position by contact with said switch actuator when the tester extension is extended in its normal testing position and to move outwardly to the switch opening position whenever the switch actuator moves away from said plunger incidental to a displacement of the tester extension by a bent edge portion of a blank and a spring pressed plunger disposed in the vertical plane in which the switch actuator lies when the tester extension is extended in its normal testing position, said actuator and plunger having cooperatively engaging detent means effective when in cooperative engagement to hold the acuator against the switch plunger.

JUSTIN SIMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 1,673,222 Bonebrake June 12, 1928 1,792,979 Greenleaf et a1 Feb. 17, 1931 2,323,351 Pechy July 6, 1943 2,452,223 Cady et al Oct. 26, 1948 

